From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:56907 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751823AbbIOO4H (ORCPT ); Tue, 15 Sep 2015 10:56:07 -0400 Subject: Re: kernel BUG at linux-4.2.0/fs/btrfs/extent-tree.c:1833 on rebalance To: =?UTF-8?Q?St=c3=a9phane_Lesimple?= , References: <9c864637fe7676a8b7badc5ddd7a4e0c@all.all> <2c00c4b7c15e424659fb2e810170e32e@all.all> From: Josef Bacik Message-ID: <55F83181.9010201@fb.com> Date: Tue, 15 Sep 2015 10:56:01 -0400 MIME-Version: 1.0 In-Reply-To: <2c00c4b7c15e424659fb2e810170e32e@all.all> Content-Type: text/plain; charset="utf-8"; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 09/15/2015 10:47 AM, Stéphane Lesimple wrote: >> I've been experiencing repetitive "kernel BUG" occurences in the past >> few days trying to balance a raid5 filesystem after adding a new drive. >> It occurs on both 4.2.0 and 4.1.7, using 4.2 userspace tools. > > I've ran a scrub on this filesystem after the crash happened twice, and > if found no errors. > > The BUG_ON() condition that my filesystem triggers is the following : > > BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID); > // in insert_inline_extent_backref() of extent-tree.c. > > I've compiled a fresh 4.3.0-rc1 with a couple added printk's just before > the BUG_ON(), to dump the parameters passed to > insert_inline_extent_backref() when the problem occurs. > Here is an excerpt of the resulting dmesg : > > {btrfs} in insert_inline_extent_backref, got owner < > BTRFS_FIRST_FREE_OBJECTID > {btrfs} with bytenr=4557830635520 num_bytes=16384 parent=4558111506432 > root_objectid=3339 owner=1 offset=0 refs_to_add=1 > BTRFS_FIRST_FREE_OBJECTID=256 > ------------[ cut here ]------------ > kernel BUG at fs/btrfs/extent-tree.c:1837! > > I'll retry with the exact same kernel once I get the machine back up, > and see if the the bug happens again at the same filesystem spot or a > different one. > The variable amount of time after a balance start elapsed before I get > the bug suggests that this would be a different one. > Does btrfsck complain at all? Thanks, Josef